<!DOCTYPE HTML>
<html lang="en-US" >
    
    <head>
        
        <meta charset="UTF-8">
        <title>对象和方法之间的关系 | </title>
        <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
        <meta name="description" content="">
        <meta name="generator" content="GitBook 1.0.3">
        <meta name="HandheldFriendly" content="true"/>
        <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
        <meta name="apple-mobile-web-app-capable" content="yes">
        <meta name="apple-mobile-web-app-status-bar-style" content="black">
        <link rel="apple-touch-icon-precomposed" sizes="152x152" href="gitbook/images/apple-touch-icon-precomposed-152.png">
        <link rel="shortcut icon" href="gitbook/images/favicon.ico" type="image/x-icon">
        
    
    
    
    <link rel="next" href="./pragma_mark/README.html" />
    
    
    <link rel="prev" href="./5.html" />
    

        
    </head>
    <body>
        
        
<link rel="stylesheet" href="gitbook/style.css">


        
    <div class="book"  data-level="3" data-basepath="." data-revision="1442487071738">
    

<div class="book-summary">
    <div class="book-search">
        <input type="text" placeholder="Type to search" class="form-control" />
    </div>
    <ul class="summary">
        
    	
    	
    	

        

        
    
        
        <li class="chapter " data-level="0" data-path="index.html">
            
                
                    <a href="./index.html">
                        <i class="fa fa-check"></i>
                        
                         保持兴奋
                    </a>
                
            
            
        </li>
    
        
        <li class="chapter " data-level="1" data-path="nsstring/README.html">
            
                
                    <a href="./nsstring/README.html">
                        <i class="fa fa-check"></i>
                        
                            <b>1.</b>
                        
                         NSString 类介绍及用法
                    </a>
                
            
            
        </li>
    
        
        <li class="chapter " data-level="2" data-path="5.html">
            
                
                    <a href="./5.html">
                        <i class="fa fa-check"></i>
                        
                            <b>2.</b>
                        
                         结构体成员变量
                    </a>
                
            
            
        </li>
    
        
        <li class="chapter active" data-level="3" data-path="4.html">
            
                
                    <a href="./4.html">
                        <i class="fa fa-check"></i>
                        
                            <b>3.</b>
                        
                         对象和方法之间的关系
                    </a>
                
            
            
        </li>
    
        
        <li class="chapter " data-level="4" data-path="pragma_mark/README.html">
            
                
                    <a href="./pragma_mark/README.html">
                        <i class="fa fa-check"></i>
                        
                            <b>4.</b>
                        
                         #pragma mark指令
                    </a>
                
            
            
        </li>
    
        
        <li class="chapter " data-level="5" data-path="6.html">
            
                
                    <a href="./6.html">
                        <i class="fa fa-check"></i>
                        
                            <b>5.</b>
                        
                         对象作为方法的参数连续传递
                    </a>
                
            
            
        </li>
    
        
        <li class="chapter " data-level="6" data-path="oc/README.html">
            
                
                    <a href="./oc/README.html">
                        <i class="fa fa-check"></i>
                        
                            <b>6.</b>
                        
                         OC多文件开发介绍
                    </a>
                
            
            
        </li>
    
        
        <li class="chapter " data-level="7" data-path="8.html">
            
                
                    <a href="./8.html">
                        <i class="fa fa-check"></i>
                        
                            <b>7.</b>
                        
                         匿名对象
                    </a>
                
            
            
        </li>
    
        
        <li class="chapter " data-level="8" data-path="xcode/README.html">
            
                
                    <a href="./xcode/README.html">
                        <i class="fa fa-check"></i>
                        
                            <b>8.</b>
                        
                         Xcode模板修改
                    </a>
                
            
            
        </li>
    
        
        <li class="chapter " data-level="9" data-path="9.html">
            
                
                    <a href="./9.html">
                        <i class="fa fa-check"></i>
                        
                            <b>9.</b>
                        
                         Xcode文档安装
                    </a>
                
            
            
        </li>
    


        
        <li class="divider"></li>
        <li>
            <a href="http://www.gitbook.io/" target="blank" class="gitbook-link">Published using GitBook</a>
        </li>
        
    </ul>
</div>

    <div class="book-body">
        <div class="body-inner">
            <div class="book-header">
    <!-- Actions Left -->
    <a href="#" class="btn pull-left toggle-summary" aria-label="Toggle summary"><i class="fa fa-align-justify"></i></a>
    <a href="#" class="btn pull-left toggle-search" aria-label="Toggle search"><i class="fa fa-search"></i></a>
    
    <div id="font-settings-wrapper" class="dropdown pull-left">
        <a href="#" class="btn toggle-dropdown" aria-label="Toggle font settings"><i class="fa fa-font"></i>
        </a>
        <div class="dropdown-menu font-settings">
    <div class="dropdown-caret">
        <span class="caret-outer"></span>
        <span class="caret-inner"></span>
    </div>

    <div class="buttons">
        <button type="button" id="reduce-font-size" class="button size-2">A</button>
        <button type="button" id="enlarge-font-size" class="button size-2">A</button>
    </div>

    <div class="buttons font-family-list">
        <button type="button" data-font="0" class="button">Serif</button>
        <button type="button" data-font="1" class="button">Sans</button>
    </div>

    <div class="buttons color-theme-list">
        <button type="button" id="color-theme-preview-0" class="button size-3" data-theme="0">White</button>
        <button type="button" id="color-theme-preview-1" class="button size-3" data-theme="1">Sepia</button>
        <button type="button" id="color-theme-preview-2" class="button size-3" data-theme="2">Night</button>
    </div>
</div>

    </div>

    <!-- Actions Right -->
    
    <div class="dropdown pull-right">
        <a href="#" class="btn toggle-dropdown" aria-label="Toggle share dropdown"><i class="fa fa-share-alt"></i>
        </a>
        <div class="dropdown-menu font-settings dropdown-left">
            <div class="dropdown-caret">
                <span class="caret-outer"></span>
                <span class="caret-inner"></span>
            </div>
            <div class="buttons">
                <button type="button" data-sharing="twitter" class="button">Twitter</button>
                <button type="button" data-sharing="google-plus" class="button">Google</button>
                <button type="button" data-sharing="facebook" class="button">Facebook</button>
                <button type="button" data-sharing="weibo" class="button">Weibo</button>
                <button type="button" data-sharing="instapaper" class="button">Instapaper</button>
            </div>
        </div>
    </div>
    

    
    <a href="#" target="_blank" class="btn pull-right google-plus-sharing-link sharing-link" data-sharing="google-plus" aria-label="Share on Google Plus"><i class="fa fa-google-plus"></i></a>
    
    
    <a href="#" target="_blank" class="btn pull-right facebook-sharing-link sharing-link" data-sharing="facebook" aria-label="Share on Facebook"><i class="fa fa-facebook"></i></a>
    
    
    <a href="#" target="_blank" class="btn pull-right twitter-sharing-link sharing-link" data-sharing="twitter" aria-label="Share on Twitter"><i class="fa fa-twitter"></i></a>
    
    

    <!-- Title -->
    <h1>
        <i class="fa fa-circle-o-notch fa-spin"></i>
        <a href="./" ></a>
    </h1>
</div>

            <div class="page-wrapper" tabindex="-1">
                <div class="page-inner">
                
                
                    <section class="normal" id="section-gitbook_24">
                    
                        <h1 id="">对象和方法之间的关系</h1>
<h2 id="">本小节知识点:</h2>
<ol>
<li>【掌握】对象作为方法的参数</li>
<li>【掌握】对象作为方法的返回值</li>
</ol>
<hr>
<p><img src="images/a3/109957938731.jpg" alt=""></p>
<p><img src="images/a3/9c16fdfaaf51f3de775642d194eef01f3b29799b.png" alt=""></p>
<h2 id="1">1.对象作为方法的参数</h2>
<ul>
<li>对象作为方法参数传递是地址传递，因为对象是一个指针变量</li>
<li>在方法内部，可以通过对象形参，访问该对象的成员变量(如果该对象的该成员变量的访问权限是public的)</li>
<li>在方法内部，可以通过对象形参，调用该对象上的方法（给这个对象发送消息）</li>
</ul>
<pre><code class="lang-objc"><span class="hljs-keyword">int</span> main(<span class="hljs-keyword">int</span> argc, <span class="hljs-keyword">const</span> <span class="hljs-keyword">char</span> * argv[])
{
    <span class="hljs-comment">//    1.创建士兵对象</span>
    Soldier *s1 = [Soldier new];
    s1-&gt;_name = <span class="hljs-string">@"jack"</span>;
    s1-&gt;_life = <span class="hljs-number">10</span>;
    s1-&gt;_level = kSoldierLevel1;

    <span class="hljs-comment">//    2.创建枪对象</span>
    Gun *gun = [Gun new];
    gun-&gt;_bulletCount = <span class="hljs-number">100</span>;

    <span class="hljs-comment">//    3.射击</span>
    [s1 fireByGun:gun];
}

<span class="hljs-class"><span class="hljs-keyword">@implementation</span> <span class="hljs-title">Soldier</span></span>

- (<span class="hljs-keyword">void</span>)fireByGun:(Gun *)gun
{
    [gun shoot];
}

<span class="hljs-keyword">@end</span>
</code></pre>
<hr>
<h2 id="2">2.对象作为方法的返回值</h2>
<ul>
<li>对象可以作为方法的返回值；</li>
<li>对象返回值的实质是返回指向该对象的指针，该对象是存储在堆内存中的。</li>
<li>由于堆内存是由程序员管理的，所以它不会因为函数结束而被销毁</li>
</ul>
<pre><code class="lang-objc"><span class="hljs-class"><span class="hljs-keyword">@implementation</span> <span class="hljs-title">Shop</span></span>

- (Gun *)buyGun
{
    Gun *gun = [Gun new];
    gun-&gt;_bulletCount = <span class="hljs-number">100</span>;
    <span class="hljs-keyword">return</span> gun;
}

<span class="hljs-keyword">@end</span>
</code></pre>

                    
                    </section>
                
                
                </div>
            </div>
        </div>

        
        <a href="./5.html" class="navigation navigation-prev " aria-label="Previous page: 结构体成员变量"><i class="fa fa-angle-left"></i></a>
        
        
        <a href="./pragma_mark/README.html" class="navigation navigation-next " aria-label="Next page: #pragma mark指令"><i class="fa fa-angle-right"></i></a>
        
    </div>
</div>

        
<script src="gitbook/app.js"></script>

    
    <script src="https://cdn.mathjax.org/mathjax/2.4-latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
    

    
    <script src="gitbook/plugins/gitbook-plugin-mathjax/plugin.js"></script>
    

<script>
require(["gitbook"], function(gitbook) {
    var config = {"fontSettings":{"theme":null,"family":"sans","size":2}};
    gitbook.start(config);
});
</script>

        
    </body>
    
</html>
